1. Field of the Invention
The present invention relates to signal processing techniques. More particularly, the present invention relates to methods for decomposing audio signals using similarity metrics.
2. Description of the Related Art
Primary-ambient decomposition algorithms separate the reverberation (and diffuse, unfocussed sources) from the primary coherent sources in a stereo or multichannel audio signal. This is useful for audio enhancement (such as increasing or decreasing the “liveliness” of a track), upmix (for example, where the ambience information is used to generate synthetic surround signals), and spatial audio coding (where different methods are needed for primary and ambient signal content).
Current methods determine the similarity of audio channels based on a real-valued similarity metric, and use that metric to estimate primary and/or ambient components. Unfortunately, these techniques sometimes result in artifacts in the audio rendering. What is desired is an improved primary-ambient decomposition technique.